PURPOSE: To compensate the halation part of an image caused by the change of a photographic angle to an examinee in all the phases in a series of radiographing.

CONSTITUTION: A detection signal from an encoder 7 for detecting the rotating angle position of a rotary supporter is inputted to an iris controller 9 and inside this iris controller 9, a position information memory 28 is installed to store rotating angle information from the encoder and the position information of iris fans 14a and 14b for limitation inside an iris device 8 while making them correspondent each other. Further, at the time of radiograph, the position information of the iris fans 14a and 14b for limitation is read from the position information memory 28, and the iris pattern is set synchronously with the radiographing angle. Thus, the halation part of the image caused by the change of the radiographic angle to the examinee can be compensated in all the phases in a series of radiograph.